Conceptually, a net-zero energy building (NZEB) is a residential or a commercial building that produces as much energy as it consumes over the period of a year. This technology has highly reduced energy requirements, and the efficacy advantages have been made in such a way that the deficit of energy needed can be sourced from the renewable energy sources. NZEB combines a prototypical building designed to reduce energy consumption, having restorable schemes that meet the decreased requirements. The NZEBs are classified depending on the renewable sources a home uses. If the house uses the energy available on-site, it is at the top of the NZEB classification structure. Disparately, a building that qualifies to be called an NZEB with respect to a use of both renewable sources on-site as well as from off-site falls at the bottom of the classification. The owners and the designers of these houses should first use all attainable cost-friendly energy efficiency approaches, then use renewable sources and technologies available within the footprint (Sionshansi, 2013).
Buildings have a momentous impact on the environment and energy use. They are important causes as well as the potential answers to power insecurity and climate change. Buildings, both commercial and residential, use almost forty percent of the primary energy and approximately seventy percent of it in America. Similarly, in the US, buildings consume nearly forty-five percent of the total energy of the country and contribute almost forty percent of greenhouse gas (GHG) emissions. This represents eight percent of GHG releases globally, an amount equivalent to the total number of the whole India (EIA, 2005). Many initiatives advocate improved energy efficiencies in constructions, which save power and lessen the damage to the environment. The sustainability of these buildings is based on the improved energy consumption and the reduction of the related natural impacts. The NZEB are designed in such way that they can self-sustain on the renewable energy produced on-site and opt for non-renewable sources only in case of shortages. On occasion, the power generated by the house is excessive the surplus is exported to the nation’s grid. Today, a growing number of NZEBs is in existence in the US. As such, numerous programs and policies are coming up to support their international adoption. (Sioshansi, 2013)
This paper analyzes the sustainability of one of the NZEBs in America, namely the Honda Smart Home at UC Davis West Village.
THE HONDA SMART HOME (HSH)
HSH is a project that was started in April, 2013. It is a combined activity of the Honda Motor Company and the University of California. The project is concentrated on California State but hopes to expand across the nation. HSH can be considered as the residence with the green features and also the most sustainable home in terms of management and the overall running of the house. The construction in UC Davis, West Village was built with a blend of technologies that allows zero net energy living and locomotion. It has a capability of generating more power on-site than it consumes per year using renewable sources. The production includes enough energy to charge a Honda fit electrical vehicle for daily transportation. HSH is the initial single unitary household to be constructed and it will act as a life laboratory for some years. The HSH was primarily designed to address certain problems related to the energy sector and the transportation industry in the U.S. (Honda Smart Home, 2014).
The major vision of the project is to steer zero carbon living in homes as well as in personal mobility. The other goal is to produce new technology that will be inculcated into the business sector, housing projects, transportation, the energy sector, and the environment in general. In the existing systems, the goal is to improve the conservation and usage of available resources such as water and electricity (Sinclair, 2014). This is achieved through the utilization of green materials, the solar energy, and the waste materials from industries and other consumers. These are spearheaded to the major consumption areas of homes, which are the heating, lighting, and cooling, as well as the energy for transportation of individuals.
On a broader perspective, West Village itself is headed to attaining its goal of operating as a zero net energy community. In 2013, it generated eighty-seven percent of the power utilized in a course of one year period. The project began in April, 2013 as a sustainable living project and is intended to go beyond family unit’s transportation and confront the two important sources of CO2 emissions: homes and vehicles. Presently, the total energy used in a typical home is very high. It follows that fully powering houses, and light duty commuter vehicles account for about forty-five percent of GHG emissions across the US. The technology that allows using the disseminated renewable energy production in homes and by vehicles is one of the most important potential strategies to combat the issue of climate change (Honda Smart Home, 2014).
HOW THE HSH WORKS AND ITS SUSTAINABILITY FEATURES
The foundation of ZNE strategies at UC Davis, West Village is power efficiency. The planners and the designers of the house realized that in order to meet the ZNE goals with renewable energy, they had to tremendously cut down below the City’s standards the energy requirements of West Village. The energy strategies have notably evolved over the time between the conception and the opening of the project. The house is designed with several saving elements planned to considerably lower the building and lighting energy, power for running the household appliances, as well as the for other miscellaneous uses. First, the Honda Smart Home projects are made with green features. The HSH also implements HEMS (Honda’s home energy management system), which is an exclusive hardware and software system that keeps track, controls, and adjusts energy generation and consumption within the building’s microgrid.
Honda’s home energy management system (Honda Smart Home, 2014)
The walls of the houses are made of double studs, mainly from the locally available materials which provide a lot of insulation from heat and cold. The floors are mainly made of wood and recycled content tiles (Honda Smart Home, 2014). On the other hand, the doors are produced in Oregon using strong double studs. The furnishings of these structures are made of simple studs which include stove tops, cabinets, and cooling cabinets. The tables, the mattresses, and all the other furnishings in the home are made of recycled materials (Bhise, 2013). Paints used for the homes are Cabius, which are prepared locally from organic materials. This cuts down on the overall construction cost of the houses.
Modeled Energy Savings with West Village Efficiency Package (Honda Smart Home, 2014)
HSH employs a ‘passive design’ technique whereby it is made to be highly efficient through the utilization of the local weather conditions, the direction of the sun, and the outer wall of the home. The windows facing south are for heating and cooling while those facing north are strategically placed to increase natural lighting as well as ventilation. The plan keeps the building naturally cool and warm in the summer and winter consecutively. The house is air conditioned through the radiant floor delivery and radiant cell panels on the first and the second floor respectively.
The heating of the homes is provided by solar power collectors and batteries that are supplied by the Honda Company. The collectors are straddled on the roof and produce more energy than it can be consumed by the house and a fit electric vehicle on a year basis. This is mostly because of the efficient design of the building. All the energy required for home running including the charging energy for a fit Honda electric vehicle is obtained from the solar panels. The vehicle is modified to accept direct current, which eradicates nearly half of energy loss that occurs during conversion of power from DC-AC and AC-DC. Also, the vehicle can fully recharge in about two hours directly from the sunlight.
Typically, the heating and the air conditioning frameworks are the major consumers of huge amounts of energy in both home and vehicle. The HSH employs an underground heating system whereby at its backyard, there are eight twenty feet deep boreholes that enable a geothermal pump to connect the comparatively stable thermal sink of the ground to heat and cool the building across the year. The performance of this system will be analyzed to decide its conventional use adaptability.
Concrete is responsible for about five percent of man-made CO2 emissions worldwide. The high footprint is a result of cement production, which is the main component of concrete, through heating of limestone to over a thousand degrees Celsius. The heating entails burning of fossil fuel, which also releases CO2. Half of the concrete used in the construction of HSH contains pozzolan, a naturally occurring substance, which replaces the cement needed. The building also utilizes a post-tensioning technique to reduce the amount of concrete and steel used in construction.
In a typical American housing unit, the toilet alone can spend twenty-seven percent of the total household water consumption. The HSH is three times more water-efficient than a typical US home. The HSH is fitted with ‘dual-flush toilets with water sense certification, low flow nozzles in the showers and sinks, double-efficiency dishwashers and washing machines to increase water saving (Patterson, 2002).
BENEFITS OF HSH
One of the benefits of the HSH is photovoltaic fitted on the roof of the home, which produces almost double of the usual amount of heat a home consumes in a day. This cuts down the electricity costs to zero percent. The excess energy is channeled to the storage facilities that have a fixable system for the charging of electric car that runs on electricity. Secondly, the designs of the homes are called ‘passive’ that take into account all the weather conditions, the direct sunshine, and the conservation of energy through the wall structure. The technique cuts down on the amount of energy required for heating and cooling but, at the same time, maintains the comfortable living environments. The homes are fitted with LED lighting that has more energy saving ability than the bulbs. The LEDs are also designed to uphold the health and the wellbeing of the occupants of the house (White, 1995). The connections of the walls use pozzolan instead of concrete. This cuts down the cement consumption whose manufacturing accounts for five percent of total carbon dioxide emissions in the globe. Cleaning and scrubbing the organic surfaces is easy, thus reducing water consumption. Air conditioning and heating normally use a relative amount of energy in most typical homes. In the HSH, this is provided by underground heating and cooling by a heat pump. The technique cuts down a lot of the energy consumed by the home. The entire materials used for the construction are sustainable since about ninety-six percent of them used in the home were recycled (Sinclair, 2014). Lastly, since it is being developed as a ‘living laboratory’ to test ideas and inventions of ZNE living and locomotion, it will produce technologies that will be applied in the housing sector in California and the US at large.
THE PROS OF THE PROJECT
First, the project surpasses the zero net energy goals that California has benchmarked for the vision 2020 and that of the nation at whole. By combining advanced technology, energy efficiency measures, as well as sustainable design techniques, the home generates more than enough power for itself and the electric vehicle daily (Woolley & Kimmins, 2000). Secondly, the surplus of the energy collected from the homes is being used to power vehicles and for other uses. Thirdly, the collaboration and sharing of data from the University and Honda Motors lays a platform for greater innovations in the future. The project reduces the carbon emissions in the world, taking into account sustainable stimulation.
CONS OF THE PROJECT
Firstly, the initial setup cost of the materials is very high for the construction of the home. It is estimated that the total investment of the project is approximately two hundred and eighty million dollars (Honda Smart Home, 2014). Secondly, the application of the project is limited to a small scale. It may be a little bit harder to put up these structures in heavy industries especially the intensive ones in terms of the load of the work being done.
VIEWS ON THE HSH PROJECT AND ITS FUTURE SUSTAINABILITY
There is a sustainability aspect of this project. Given that home consumptions of energy in the country accounts for more than half the nation’s expenditure, such infrastructure would bring the cost of power down as well as the production cost of goods and services and the cost of transportation in the sector (Bahr, 1997).
With the diminishing fuel reserves, this is one of the anchors that the future may be hooked to. An early investment will put the nation strategically in the future. Following this move, other companies like the Ford, have come up with an electric car, and Tesla is also towing the line. In future, it may be found that all cars will have an electrical system for its driving. The HSH is projected to produce approximately 2.6 MWh of electricity per year, and a typical house will use 13 MWh. This energy consumption translates to a reduction of 13 100 pounds of carbon dioxide per year. The reduction of CO2 emission is even higher since the HSH will run its transportation with the energy generated. The resultant net energy is stored in anticipation of increased needs in the future (Lippiat, 2001).
CONCLUSION
As the pioneer extensive ZNE neighborhood in the US, West Village offers a powerful model of how a nation might shift towards a ZNE status for principally residential mixed-use communities. A ZNEB is a building that produces or generates the equivalent excess energy that it uses on an annual basis. The smart home project has been recognized globally as the best demonstration of the global goal of zero carbon emission, as well as zero net energy living and locomotion. The project makes use of a combination of advanced technology and energy efficient strategies to reduce energy requirements and to obtain the needed energy from renewable sources on the ground. As the flagship project, others will come along, and there is yet to be more improvement as many will adapt the model. Although the project is only a few years old, it has made milestones, and this is seen as the homes are getting occupied currently. The project acts as a research facility for the advancement and further innovation of what has already been started.